What is open source software?
open source software is a software in which the underlying programming code is available to the users so that they may read it, make changes to it, and build new versions of the software incorporating their changes. There are many types of Open Source Software, mainly differing in the licensing term under which (altered) copies of the source code may (or must be) redistributed. Besides that open source softwre must comply with the nine policies of the Open Source Organization. List of commonly use open source software include Firefox, Linux etc.

Open soure software for educational purposes: Reference to a scenario in India
I found an article that said how open spurce softwre was booming in India.In the article it says that almost all the schools of the Southern part of the country now uses an open source software and it is often LInux. Cotton Hill Girls High school, a renowned 71 year old school now uses only a linux based operating system. the situation is now such that only a very few people really now what windows is. When a girl was asked what windows is she replied that she never heard of it.(!!) besides that by the end of next year all the schools will have a linux based operating system made mandatory. 18 out of 26 of India's states now uses either Linux or Windows. This is somethig Microsoft must consider as IT specialists predict that by the next few years Linux might overthrow windows.